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Author Zeng, Y.I.; Menghini, M.; Li, D.Y.; Lin, S.S.; Ye, Z.Z.; Hadermann, J.; Moorkens, T.; Seo, J.W.; Locquet, J.-P.; van Haesendonck, C.
Title Unexpected optical response of single ZnO nanowires probed using controllable electrical contacts Type A1 Journal article
Year 2011 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 13 Issue 15 Pages 6931-6935
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Relying on combined electron-beam lithography and lift-off methods Au/Ti bilayer electrical contacts were attached to individual ZnO nanowires (NWs) that were grown by a vapor phase deposition method. Reliable Schottky-type as well as ohmic contacts were obtained depending on whether or not an ion milling process was used. The response of the ZnO NWs to ultraviolet light was found to be sensitive to the type of contacts. The intrinsic electronic properties of the ZnO NWs were studied in a field-effect transistor configuration. The transfer characteristics, including gate threshold voltage, hysteresis and operational mode, were demonstrated to unexpectedly respond to visible light. The origin of this effect could be accounted for by the presence of point defects in the ZnO NWs.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000288951000019 Publication Date 2011-03-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 7 Open Access
Notes Approved Most recent IF: 4.123; 2011 IF: 3.573
Call Number (down) UA @ lucian @ c:irua:89378 Serial 3807
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Author Matulis, A.; Masir, M.R.; Peeters, F.M.
Title Application of optical beams to electrons in graphene Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115458-115458,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288896400013 Publication Date 2011-03-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 13 Open Access
Notes ; This research was supported by the Flemish Science Foundation (Grant No. FWO-Vl), by the Belgian Science policy (IAP), and (in part) by the Lithuanian Science Council under project No. MIP-79/2010. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:89377 Serial 142
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Author Li, B.; Peeters, F.M.
Title Tunable optical Aharonov-Bohm effect in a semiconductor quantum ring Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115448-115448,13
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like and ring-like. The constraints on the geometrical parameters of the quantum ring to realize such a transition are derived. With such a perpendicular electric field we are able to tune the Aharanov-Bohm (AB) effect for both the single particle and for excitons. The tunability is in both the strength of the AB effect as well as in its periodicity. We also investigate the strain induce potential inside the self-assembled quantum ring and the effect of the strain on the AB effect.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288855200012 Publication Date 2011-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 25 Open Access
Notes ; This work was supported by the EU-NoE: SANDiE, the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC, vzw collaborative project. We are grateful to Prof. M. Tadic and Dr. Fei Ding for stimulating discussions. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:89376 Serial 3744
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Author Liu, C.-Y.; Berdiyorov, G.R.; Milošević, M.V.
Title Vortex states in layered mesoscopic superconductors Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 10 Pages 104524-104524,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Within the Ginzburg-Landau theory, we study the vortex structures in three-dimensional anisotropic mesoscopic superconductors in the presence of a uniform magnetic field. Anisotropy is included through varied Tc in different layers of the sample and leads to distinct differences in the vortex states and their free energy. Several unconventional states are found, some comprising vortex clusters or exhibiting asymmetry. In a tilted magnetic field, we found second-order transitions between different vortex states, although vortex entry is generally a first-order transition in mesoscopic samples. In multilayered samples the kinked vortex strings are formed owing to the competing interactions of vortices with Meissner currents and the weak-link boundaries. The length and deformation of vortex fragments are determined solely by the inclination and strength of applied magnetic field, and this lock-in does not depend on the degree of anisotropy between the superconducting layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288998200003 Publication Date 2011-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 22 Open Access
Notes ; ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:89375 Serial 3888
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Author Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Groeseneken, G.; Fischetti, M.V.
Title Impact of field-induced quantum confinement in tunneling field-effect devices Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 14 Pages 143503,1-143503,3
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000289297800074 Publication Date 2011-04-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 76 Open Access
Notes ; The authors acknowledge Anne Verhulst for useful discussions. William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by IMEC's Industrial Affiliation Program. ; Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number (down) UA @ lucian @ c:irua:89297 Serial 1559
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Author Nga, T.T.N.; Peeters, F.M.
Title Influence of electron-electron interaction on the cyclotron resonance spectrum of magnetic quantum dots containing few electrons Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 7 Pages 075419-075419,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The configuration interaction method is used to obtain the magneto-optical absorption spectrum of a few-electron (Ne=1,2,,5) quantum dot containing a single magnetic ion. We find that the IR spectrum (the position, the number, and the oscillator strength of the cyclotron resonance peaks) depends on the strength of the Coulomb interaction, the number of electrons, and the position of the magnetic ion. We find that the Kohn theorem is no longer valid as a consequence of the electron-spin-magnetic-ion-spin-exchange interaction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000287584600011 Publication Date 2011-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 8 Open Access
Notes ; This work was supported by FWO-Vl (Flemish Science Foundation), the Brazilian science foundation CNPq, and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:88912 Serial 1620
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Author Barbier, M.; Vasilopoulos, P.; Peeters, F.M.
Title Kronig-Penney model on bilayer graphene : spectrum and transmission periodic in the strength of the barriers Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 23 Pages 235408-235408,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We show that the transmission through single and double δ-function potential barriers of strength P=VWb/ℏvF in bilayer graphene is periodic in P with period π. For a certain range of P values we find states that are bound to the potential barrier and that run along the potential barrier. Similar periodic behavior is found for the conductance. The spectrum of a periodic succession of δ-function barriers (Kronig-Penney model) in bilayer graphene is periodic in P with period 2π. For P smaller than a critical value Pc, the spectrum exhibits two Dirac points while for P larger than Pc an energy gap opens. These results are extended to the case of a superlattice of δ-function barriers with P alternating in sign between successive barriers; the corresponding spectrum is periodic in P with period π.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000286766900008 Publication Date 2010-12-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 34 Open Access
Notes ; This work was supported by IMEC, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the Canadian NSERC under Grant No. OGP0121756. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number (down) UA @ lucian @ c:irua:88910 Serial 1768
Permanent link to this record
 
 
Author Li, L.L.; Xu, W.; Peeters, F.M.
Title Intrinsic optical anisotropy of [001]-grown short-period InAs/GaSb superlattices Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 23 Pages 235422-235422,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We theoretically investigate the intrinsic optical anisotropy or polarization induced by the microscopic interface asymmetry (MIA) in no-common-atom (NCA) InAs/GaSb superlattices (SLs) grown along the [001] direction. The eight-band K⋅P model is used to calculate the electronic band structures and incorporates the MIA effect. A Boltzmann equation approach is employed to calculate the optical properties. We found that in NCA InAs/GaSb SLs, the MIA effect causes a large in-plane optical anisotropy for linearly polarized light and the largest anisotropy occurs for light polarized along the [110] and [11̅ 0] directions. The relative difference between the optical-absorption coefficient for [110]-polarized light and that for [11̅ 0]-polarized light is found to be larger than 50%. The dependence of the in-plane optical anisotropy on temperature, photoexcited carrier density, and layer width is examined in detail. This study is important for optical devices which require the polarization control and selectivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000286768800007 Publication Date 2010-12-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 18 Open Access
Notes ; This work was supported partly by the Flemish Science Foundation (FWO-VL), the Belgium Science Policy (IAP), the NSF of China (Grants No. 10664006, No. 10504036, and No. 90503005), Special Funds of 973 Project of China (Grant No. 2005CB623603), and Knowledge Innovation Program of the Chinese Academy of Sciences. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number (down) UA @ lucian @ c:irua:88909 Serial 1717
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Author Hao, Y.L.; Djotyan, A.P.; Avetisyan, A.A.; Peeters, F.M.
Title D- shallow donor near a semiconductor-metal and a semiconductor-dielectric interface Type A1 Journal article
Year 2011 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 23 Issue 11 Pages 115303,1-115313,9
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The ground state energy and the extent of the wavefunction of a negatively charged donor (D − ) located near a semiconductormetal or a semiconductordielectric interface are obtained. We apply the effective mass approximation and use a variational two-electron wavefunction that takes into account the influence of all image charges that arise due to the presence of the interface, as well as the correlation between the two electrons bound to the donor. For a semiconductormetal interface, the D − binding energy is enhanced for donor positions d > 1.5aB (aB is the effective Bohr radius) due to the additional attraction of the electrons with their images. When the donor approaches the interface (i.e. d < 1.5aB) the D − binding energy drops and eventually it becomes unbound. For a semiconductordielectric (or a semiconductorvacuum) interface the D − binding energy is reduced for any donor position as compared to the bulk case and the system becomes rapidly unbound when the donor approaches the interface.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000287969200013 Publication Date 2011-03-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 5 Open Access
Notes ; This work was supported by the Belgian Science Policy (IAP) and the Brazilian Science Foundation CNPq. One of us (AAA) was supported by a fellowship from the Belgian Federal Science Policy Office (IAP). ; Approved Most recent IF: 2.649; 2011 IF: 2.546
Call Number (down) UA @ lucian @ c:irua:88828 Serial 3528
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Author Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V.
Title Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides Type A1 Journal article
Year 2011 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 133 Issue 4 Pages 692-694
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000287295300015 Publication Date 2010-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 28 Open Access
Notes Approved Most recent IF: 13.858; 2011 IF: 9.907
Call Number (down) UA @ lucian @ c:irua:88820 Serial 1236
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Author Chaves, A.; Peeters, F.M.; Farias, G.A.; Milošević, M.V.
Title Vortex-vortex interaction in bulk superconductors : Ginzburg-Landau theory Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 5 Pages 054516-054516,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The vortex-vortex interaction potential in bulk superconductors is calculated within the Ginzburg-Landau (GL) theory and is obtained from a numerical solution of a set of two coupled nonlinear GL differential equations for the vector potential and the superconducting order parameter, where the merger of vortices into a giant vortex is allowed. Further, the interaction potentials between a vortex and a giant vortex and between a vortex and an antivortex are obtained for both type-I and type-II superconductors. Our numerical results agree asymptotically with the analytical expressions for large intervortex separations that are available in the literature. We propose empirical expressions valid over the full interaction range, which are fitted to our numerical data for different values of the GL parameter.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000287712100009 Publication Date 2011-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 31 Open Access
Notes ; Discussions with J. S. Andrade Jr. and A. A. Moreira are gratefully acknowledged. This work was financially supported by CNPq, under Contract No. NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES, the Bilateral programme between Flanders and Brazil, the collaborative project CNPq-FWO-Vl, the Belgian Science Policy (IAP), and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:88805 Serial 3899
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Author Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M.
Title Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples Type A1 Journal article
Year 2011 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 83 Issue 4 Pages 1214-1223
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000287176900011 Publication Date 2011-02-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2700;1520-6882; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.32 Times cited 113 Open Access
Notes Iuap; Fwo Approved Most recent IF: 6.32; 2011 IF: 5.856
Call Number (down) UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 Serial 632
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Author Kirsanova, M.A.; Olenev, A.V.; Abakumov, A.M.; Bykov, M.A.; Shevelkov, A.V.
Title Extension of the clathrate family : the type X clathrate Ge79P29S18Te6 Type A1 Journal article
Year 2011 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit
Volume 50 Issue 10 Pages 2371-2374
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow).
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000288036300033 Publication Date 2011-01-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 23 Open Access
Notes Approved Most recent IF: 11.994; 2011 IF: 13.455
Call Number (down) UA @ lucian @ c:irua:88793 Serial 1158
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Author Dideykin, A.; Aleksenskiy, A.E.; Kirilenko, D.; Brunkov, P.; Goncharov, V.; Baidakova, M.; Sakseev, D.; Vul', A.Y.
Title Monolayer graphene from graphite oxide Type A1 Journal article
Year 2011 Publication Diamond and related materials Abbreviated Journal Diam Relat Mater
Volume 20 Issue 2 Pages 105-108
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Graphene, a new carbon material, is attracting presently an increasing research interest. It stems from the unique electrical and mechanical properties of graphene predicted by theory. Experimental studies of graphene are, however, severely curtailed by a lack of an appropriate technique for its preparation. Mechanical cleavage of graphite proved to be ineffective, since it yields only very small (a few microns in size) particles of monolayer graphene. The rapidly developing approach based on chemical exfoliation of graphite produces large-area coatings composed primarily of arbitrarily oriented multilayer graphene particles. We have developed a technique for preparation of monolayer graphene sheets involving liquid exfoliation of crystalline graphite, which includes synthesis of graphite oxide by deep oxidation as an intermediate stage. Electron diffraction traces, as well as the variation of diffracted intensities with local orientation of graphene sheets, AFM, and HRTEM images testify to a remarkably good monolayer structure of the graphite oxide particles obtained by our technique. These results open a way to setting up high-efficiency production of monolayer graphene sheets appropriate for electrical and optical measurements and fabrication of structures for use in the field of applications.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000288145500010 Publication Date 2010-10-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-9635; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.561 Times cited 48 Open Access
Notes Approved Most recent IF: 2.561; 2011 IF: 1.913
Call Number (down) UA @ lucian @ c:irua:88791 Serial 2193
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Author Carvalho, J.C.N.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M.
Title Yukawa particles confined in a channel and subject to a periodic potential : ground state and normal modes Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 9 Pages 094109-094109,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We consider a classical system of two-dimensional (2D) charged particles, interacting through a repulsive Yukawa potential exp(-r/λ)/r, and confined in a parabolic channel that limits the motion of the particles in the y direction. Along the x direction, the particles are subject to a periodic potential. The ground-state configurations and the normal-mode spectra of the system are obtained as a function of the periodicity and strength of the periodic potential (V0) and density. An interesting set of tunable ground-state configurations are found, with first- or second-order structural transitions between them. A configuration with particles aligned, perpendicular to the x direction, in each minimum of the periodic potential is obtained for V0 larger than some critical value that has a power-law dependence on the density. The phonon spectrum of different configurations was also calculated. A localization of the modes into a small frequency interval is observed for sufficiently large strength of the periodic potential, and a tunable gap in the phonon spectrum is found as a function of V0.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288119700001 Publication Date 2011-03-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 9 Open Access
Notes ; This work was supported by the Brazilian agencies CNPq and FUNCAP (PRONEX-Grant), and the bilateral projects between Flanders and Brazil and the Flemish Science Foundation (FWO-VI) and CNPq. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:88779 Serial 3928
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Author Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M.
Title High-temperature conductance of a two-dimensional superlattice controlled by spin-orbit interaction Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115313-115313,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Rashba-type spin-orbit interaction (SOI) controlled band structure of a two-dimensional superlattice allows for the modulation of the conductance of finite size devices by changing the strength of the SOI. We consider rectangular arrays and find that the temperature dependence of the conductance disappears for high temperatures, but the strength of the SOI still affects the conductance at these temperatures. The modulation effect can be seen even in the presence of strong dephasing, which can be important for practical applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288242800007 Publication Date 2011-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 8 Open Access
Notes ; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and M045596 and by the “TAMOP-4.2.1/B-09/1/KONV-2010-0005 project: Creating the Center of Excellence at the University of Szeged” supported by the EU and the European Regional Development Fund. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number (down) UA @ lucian @ c:irua:88778 Serial 1466
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Author Kapra, A.V.; Misko, V.R.; Vodolazov, D.Y.; Peeters, F.M.
Title The guidance of vortex-antivortex pairs by in-plane magnetic dipoles in a superconducting finite-size film Type A1 Journal article
Year 2011 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 24 Issue 2 Pages 024014-024014,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The possibility of manipulating vortex matter by using various artificial pinning arrays is of significant importance for possible applications in nano and micro fluxonics devices. By numerically solving the time-dependent GinzburgLandau equations, we study the vortexantivortex (vav) dynamics in a hybrid structure consisting of a finite-size superconductor with magnetic dipoles on top which generate vav pairs in the presence of an external current. The vav dynamics is analyzed for different arrangements and magnetic moments of the dipoles, as a function of angle α between the direction of the magnetic dipole and that of the Lorentz force produced by the applied current. The interplay of the attractive interaction between a vav pair and the Lorentz force leads either to the separation of (anti)vortices and their motion in opposite directions or to their annihilation. We found a critical angle αc, below which vortices and antivortices are repelled, while for larger angles they annihilate. In case of a single (few) magnetic dipole(s), this magnetic dipole induced vav guidance is influenced by the self-interaction of the vav pairs with their images in a finite-size sample, while for a periodic array of dipoles the guidance is determined by the interaction of a vav pair with other dipoles and vav pairs created by them. This effect is tunable through the external current and the magnetization and size of the magnetic dipoles.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000286379900015 Publication Date 2011-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 28 Open Access
Notes ; This work was supported by the 'Odysseus' program of the Flemish Government and the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles (IAP) Programme-Belgian State-Belgian Science Policy, and the FWO-Vl. DYV acknowledges support from the Russian Fund for Basic Research and Russian Agency of Education under the Federal Programme 'Scientific and educational personnel of innovative Russia in 2009-2013'. ; Approved Most recent IF: 2.878; 2011 IF: 2.662
Call Number (down) UA @ lucian @ c:irua:88732 Serial 1399
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Author Milošević, M.V.; Peeters, F.M.; Jankó, B.
Title Vortex manipulation in superconducting films with tunable magnetic topology Type A1 Journal article
Year 2011 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 24 Issue 2 Pages 024001-024001,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using a combination of the phenomenological GinzburgLandau theory and micromagnetic simulations, we study properties of a superconducting film with an array of soft magnetic dots on top. An external in-plane magnetic field gradually drives the magnets from an out-of-plane or magnetic vortex state to an in-plane single-domain state, which changes spatially the distribution of the superconducting condensate. If induced by the magnets, the vortexantivortex molecules exhibit rich transitions as a function of the applied in-plane field. At the same time, we show how the magnetic dots act as very effective dynamic pinning centers for vortices in an applied perpendicular magnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000286379900002 Publication Date 2011-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 8 Open Access
Notes ; This research was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the JSPS/ESF-NES program, the bilateral project between Flanders and the USA, NSF NIRT, ECS-0609249, and the Institute for Theoretical Sciences. ; Approved Most recent IF: 2.878; 2011 IF: 2.662
Call Number (down) UA @ lucian @ c:irua:88731 Serial 3870
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Author Madani, M.; Bogaerts, A.; Vangeneugden, D.
Title Numerical modelling for a dielectric barrier discharge at atmospheric pressure in nitrogen Type P1 Proceeding
Year 2005 Publication Abbreviated Journal
Volume Issue Pages 53-56
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this paper we used a one dimensional fluid model, for the simulations of a Dielectric Barrier Discharge at atmospheric pressure. From the current and voltage profiles and the density profiles, we notice that two different regimes can be obtained in a uniform DBD. Furthermore a two dimensional flud model was developed and we describe how the gasflow can be included in such a model.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-90-808669-2-8 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number (down) UA @ lucian @ c:irua:88728 Serial 2399
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Author Paul, M.; Kufer, D.; Müller, A.; Brück, S.; Goering, E.; Kamp, M.; Verbeeck, J.; Tian, H.; Van Tendeloo, G.; Ingle, N.J.C.; Sing, M.; Claessen, R.
Title Fe3O4/ZnO : a high-quality magnetic oxide-semiconductor heterostructure by reactive deposition Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 1 Pages 012512,1-012512,3
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We demonstrate the epitaxial growth of Fe<sub>3</sub>O<sub>4</sub> films on ZnO by a simple reactive deposition procedure using molecular oxygen as an oxidizing agent. X-ray photoelectron spectroscopy results evidence that the iron-oxide surface is nearly stoichiometric magnetite. X-ray diffraction results indicate monocrystalline epitaxy and almost complete structural relaxation. Scanning transmission electron micrographs reveal that the microstructure consists of domains which are separated by antiphase boundaries or twin boundaries. The magnetite films show rather slow magnetization behavior in comparison with bulk crystals probably due to reduced magnetization at antiphase boundaries in small applied fields.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000286009800055 Publication Date 2011-01-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 27 Open Access
Notes The authors acknowledge financial support by DFG through Forschergruppe FOR 1162. Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number (down) UA @ lucian @ c:irua:88653 Serial 3532
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Author Yan, L.; Niu, H.J.; Duong, G.V.; Suchomel, M.R.; Bacsa, J.; Chalker, P.R.; Hadermann, J.; Van Tendeloo, G.; Rosseinsky, M.J.
Title Cation ordering within the perovskite block of a six-layer Ruddlesden-Popper oxide from layer-by-layer growth artificial interfaces in complex unit cells Type A1 Journal article
Year 2011 Publication Chemical science Abbreviated Journal Chem Sci
Volume 2 Issue 2 Pages 261-272
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The (AO)(ABO3)n Ruddlesden-Popper structure is an archetypal complex oxide consisting of two distinct structural units, an (AO) rock salt layer separating an n-octahedra thick perovskite block. Conventional high-temperature oxide synthesis methods cannot access members with n > 3, but low-temperature layer-by-layer thin film methods allow the preparation of materials with thicker perovskite blocks, exploiting high surface mobility and lattice matching with the substrate. This paper describes the growth of an n = 6 member CaO[(CSMO)2(LCMO)2 (CSMO)2] in which the six unit cell perovskite block is sub-divided into two central La0.67Ca0.33MnO3 (LCMO) and two terminal Ca0.85Sm0.15MnO3 (CSMO) layers to allow stabilization of the rock salt layer and variation of the transition metal charge.
Address
Corporate Author Thesis
Publisher Royal Society of Chemistry Place of Publication Cambridge Editor
Language Wos 000286327600010 Publication Date 2010-11-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-6520;2041-6539; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.668 Times cited 16 Open Access
Notes Approved Most recent IF: 8.668; 2011 IF: 7.525
Call Number (down) UA @ lucian @ c:irua:88652 Serial 300
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Author Abakumov, A.M.; Batuk, D.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Waschowski, F.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V.
Title Antiferroelectric (Pb,Bi)1-xFe1+xO3-y perovskites modulated by crystallographic shear planes Type A1 Journal article
Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 23 Issue 2 Pages 255-265
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We demonstrate for the first time a possibility to vary the anion content in perovskites over a wide range through a long-range-ordered arrangement of crystallographic shear (CS) planes. Anion-deficient perovskites (Pb,Bi)1−xFe1+xO3−y with incommensurately modulated structures were prepared as single phases in the compositional range from Pb0.857Bi0.094Fe1.049O2.572 to Pb0.409Bi0.567Fe1.025O2.796. Using a combination of electron diffraction and high-resolution scanning transmission electron microscopy, we constructed a superspace model describing a periodic arrangement of the CS planes. The model was verified by refinement of the Pb0.64Bi0.32Fe1.04O2.675 crystal structure from neutron powder diffraction data ((3 + 1)D S.G. X2/m(α0γ), X = [1/2,1/2,1/2,1/2], a = 3.9082(1) Å, b = 3.90333(8) Å, c = 4.0900(1) Å, β = 91.936(2)°, q = 0.05013(4)a* + 0.09170(3)c* at T = 700 K, RP = 0.036, RwP = 0.048). The (Pb,Bi)1−xFe1+xO3−y structures consist of perovskite blocks separated by CS planes confined to nearly the (509)p perovskite plane. Along the CS planes, the perovskite blocks are shifted with respect to each other over the 1/2[110]p vector that transforms the corner-sharing connectivity of the FeO6 octahedra in the perovskite framework to an edge-sharing connectivity of the FeO5 pyramids at the CS plane, thus reducing the oxygen content. Variation of the chemical composition in the (Pb,Bi)1−xFe1+xO3−y series occurs mainly because of a changing thickness of the perovskite block between the interfaces, that can be expressed through the components of the q vector as Pb6γ+2αBi1−7γ−αFe1+γ−αO3−3γ−α. The Pb, Bi, and Fe atoms are subjected to strong displacements occurring in antiparallel directions on both sides of the perovskite blocks, resulting in an antiferroelectric-type structure. This is corroborated by the temperature-, frequency-, and field-dependent complex permittivity measurements. Pb0.64Bi0.32Fe1.04O2.675 demonstrates a remarkably high resistivity >0.1 T Ω cm at room temperature and orders antiferromagnetically below TN = 608(10) K.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000286160800018 Publication Date 2010-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 29 Open Access
Notes Approved Most recent IF: 9.466; 2011 IF: 7.286
Call Number (down) UA @ lucian @ c:irua:88651 Serial 136
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Author Rusakov, D.; Abakumov, A.M.; Yamaura, K.; Belik, A.A.; Van Tendeloo, G.; Takayama-Muromachi, E.
Title Structural evolution of the BiFeO3-LaFeO3 system Type A1 Journal article
Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 23 Issue 2 Pages 285-292
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The (1 − x)BiFeO3−xLaFeO3 system has been investigated and characterized by room-temperature and high-temperature laboratory and synchrotron powder X-ray diffraction, electron diffraction, high-resolution transmission electron microscopy, differential scanning calorimetry, and magnetization measurements. At room temperature, the ferroelectric R3c phase is observed for 0.0 ≤ x ≤ 0.10. The PbZrO3-related √2ap × 2√2ap × 4ap superstructure (where ap is the parameter of the cubic perovskite subcell) is observed for Bi0.82La0.18FeO3, while an incommensurately modulated phase is formed for 0.19 ≤ x ≤ 0.30 with the √2ap × 2ap × √2ap basic unit cell. The GdFeO3-type phase with space group Pnma (√2ap × 2ap × √2ap) is stable at 0.50 ≤ x ≤ 1. Bi0.82La0.18FeO3 has no detectable homogeneity range (space group Pnam, a = 5.6004(1) Å, b = 11.2493(3) Å, c = 15.6179(3) Å). The incommensurately modulated Bi0.75La0.25FeO3 structure was solved from synchrotron X-ray powder diffraction data (Imma(00γ)s00 superspace group, a = 5.5956(1) Å, b = 7.8171(1) Å, c = 5.62055(8) Å, q = 0.4855(4)c*, RP = 0.023, RwP = 0.033). In this structure, cooperative displacements of the Bi and O atoms occur, which order within the (AO) (where A = Bi, La) layers, resulting in an antipolar structure. Local fluctuations of the intralayer antipolar ordering are compensated by an interaction with the neighboring (AO) layers. A coupling of the antipolar displacements with the cooperative tilting distortion of the perovskite octahedral framework is proposed as the origin of the incommensurability. All the phases transform to the GdFeO3-type structure at high temperatures. Bi0.82La0.18FeO3 shows an intermediate PbZrO3-type phase with √2ap × 2√2ap × 2ap (space group Pbam; a = 5.6154(2) Å, b = 11.2710(4) Å, and c = 7.8248(2) Å at 570 K). The compounds in the compositional range of 0.18 ≤ x ≤ 0.95 are canted antiferromagnets.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000286160800021 Publication Date 2010-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 133 Open Access
Notes Approved Most recent IF: 9.466; 2011 IF: 7.286
Call Number (down) UA @ lucian @ c:irua:88650 Serial 3236
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Author Martens, J.A.; Thybaut, J.W.; Denayer, J.F.M.; Sree, S.P.; Aerts, A.; Reyniers, M.-F.; van Speybroeck, V.; Waroquier, M.; Buekenhoudt, A.; Vankelecom, I.; Buijs, W.; Persoons, J.; Baron, G.V.; Bals, S.; Van Tendeloo, G.; Marin, G.B.; Jacobs, P.A.; Kirschhock, C.E.A.
Title Catalytic and molecular separation properties of Zeogrids and Zeotiles Type A1 Journal article
Year 2011 Publication Catalysis today Abbreviated Journal Catal Today
Volume 168 Issue 1 Pages 17-27
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Zeogrids and Zeotiles are hierarchical materials built from assembled MFI zeolite precursor units. Permanent secondary porosity in these materials is obtained through self assembly of nanoparticles encountered in MFI zeolite synthesis in the presence of supramolecular templates. Hereon, the aggregated species are termed nanoslabs. Zeogrids are layered materials with lateral spacings between nanoslabs creating galleries qualifying as supermicropores. Zeotiles present a diversity of tridimensional nanoslab assemblies with mesopores. Zeotile-1, -4 and -6 are hexagonal mesostructures. Zeotile-1 has triangular and hexagonal channels; Zeotile-4 has hexagonal channels interconnected via slits. Zeotile-2 has a cubic structure with gyroid type mesoporosity. The behavior of Zeogrids and Zeotiles in adsorption, membrane and chromatographic separation and catalysis has been characterized and compared with zeolites and mesoporous materials derived from unstructured silica sources. Shape selectivity was detected via adsorption of n- and iso-alkanes. The mesoporosity of Zeotiles can be exploited in chromatographic separation of biomolecules. Zeotiles present attractive separation properties relevant to CO2 sequestration. Because of its facile synthesis procedure without hydrothermal steps Zeogrid is convenient for membrane synthesis. The performance of Zeogrid membrane in gas separation, nanofiltration and pervaporation is reported. In the Beckmann rearrangement of cyclohexanone oxime Zeogrids and Zeotiles display a catalytic activity characteristic of silicalite-1 zeolites. Introduction of acidity and redox catalytic activity can be achieved via incorporation of Al and Ti atoms in the nanoslabs during synthesis. Zeogrids are active in hydrocracking, catalytic cracking, alkylation and epoxidation reactions. Zeogrids and Zeotiles often behave differently from ordered mesoporous materials as well as from zeolites and present a valuable extension of the family of hierarchical silicate based materials.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000291033300003 Publication Date 2011-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0920-5861; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.636 Times cited 13 Open Access
Notes Fwo; Iap Sbo Approved Most recent IF: 4.636; 2011 IF: 3.407
Call Number (down) UA @ lucian @ c:irua:88647 Serial 290
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Author Müller, M.; Turner, S.; Lebedev, O.I.; Wang, Y.; Van Tendeloo, G.; Fischer, R.A.
Title Au@MOF-5 and Au/Mox@MOF-5 (M = Zn, Ti; x = 1, 2) : preparation and microstructural characterisation Type A1 Journal article
Year 2011 Publication European journal of inorganic chemistry Abbreviated Journal Eur J Inorg Chem
Volume Issue 12 Pages 1876-1887
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The Zn-carboxylate-based porous coordination polymer MOF-5 [Zn4O(bdc)3] and the metal oxide loaded materials ZnO@MOF-5 and TiO2@MOF-5 were loaded in a second step with the precursor [ClAuCO] to yield intermediate materials denoted as [ClAuCO]@MOF-5, [ClAuCO]/ZnO@MOF-5 and [ClAuCO]/TiO2@MOF-5. These composites were decomposed to Au@MOF-5, Au/ZnO@MOF-5 and Au/TiO2@MOF-5 under hydrogen at 100 °C. The nanoparticle-loaded hybrid materials were characterised by powder X-ray diffraction (PXRD), IR spectroscopy, X-ray photoelectron spectroscopy (XPS) and N2 sorption measurements, which reveal an intact MOF-5 structure that maintains a high specific surface area. For Au@MOF-5, crystalline Au nanoparticles were distributed over the MOF matrix in a homogeneous fashion with a size of ca. 13 nm, evidenced by high resolution transmission electron microscopy. In the case of Au/ZnO@MOF-5, the Au and metal oxide particles of a few nm in size were coexistent in a given volume of the MOF-5 matrix and were not separated in different crystalline MOF particles. For the TiO2 loaded materials the oxide is preferentially located near the outer surface of the MOF particles, leading to an increase of larger exterior Au particles in comparison to very small interior Au particles as observed for the other materials. Au@MOF-5, Au/ZnO@MOF-5 and Au/TiO2@MOF-5 were tested in liquid-phase oxidation of alcohols. Preliminary results show a high activity for the Au loaded materials in this reaction. This observation is attributed to the microstructure of the composites with very small Au particles distributed homogeneously over the MOF matrix.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000289644300004 Publication Date 2011-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-1948; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.444 Times cited 75 Open Access
Notes Fwo; Esteem 026019 Approved Most recent IF: 2.444; 2011 IF: 3.049
Call Number (down) UA @ lucian @ c:irua:88644 Serial 205
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Author Canioni, R.; Roch-Marchal, C.; Sécheresse, F.; Horcajada, P.; Serre, C.; Hardi-Dan, M.; Férey, G.; Grenèche, J.-M.; Lefebvre, F.; Chang, J.-S.; Hwang, Y.-K.; Lebedev, O.; Turner, S.; Van Tendeloo, G.
Title Stable polyoxometalate insertion within the mesoporous metal organic framework MIL-100(Fe) Type A1 Journal article
Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem
Volume 21 Issue 4 Pages 1226-1233
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Successful encapsulation of polyoxometalate (POM) within the framework of a mesoporous iron trimesate MIL-100(Fe) sample has been achieved by direct hydrothermal synthesis in the absence of fluorine. XRPD, 31P MAS NMR, IR, EELS, TEM and 57Fe Mössbauer spectrometry corroborate the insertion of POM within the cavities of the MOF. The experimental Mo/Fe ratio is 0.95, in agreement with the maximum theoretical amount of POM loaded within the pores of MIL-100(Fe), based on steric hindrance considerations. The POM-MIL-100(Fe) sample exhibits a pore volume of 0.373 cm3 g−1 and a BET surface area close to 1000 m2 g−1, indicating that small gas molecules can easily diffuse inside the cavities despite the presence of heavy phosphomolybdates. These latter contribute to the decrease in the overall surface area, due to the increase in molar weight, by 65%. Moreover, the resulting Keggin containing MIL-100(Fe) solid is stable in aqueous solution with no POM leaching even after more than 2 months. In addition, no exchange of the Keggin anions by tetrabutylammonium perchlorate in organic media has been observed.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000286110400042 Publication Date 2010-11-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 158 Open Access
Notes Approved Most recent IF: NA
Call Number (down) UA @ lucian @ c:irua:88642 Serial 3145
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Author Vernimmen, J.; Meynen, V.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Cool, P.
Title Formation of a Ti-siliceous trimodal material with macroholes, mesopores and zeolitic features via a one-pot templating synthesis Type A1 Journal article
Year 2012 Publication Journal of porous materials Abbreviated Journal J Porous Mat
Volume 19 Issue 2 Pages 153-160
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Based on a facile one-pot templating synthesis, using a TS-1 zeolite recipe whereby part of the zeolite structure directing agent is replaced by a mesopore templating agent, a trimodal material is formed. The resulting meso-TSM material combines mesoporosity (Ti-MCM-41) with zeolitic features (TS-1) and a unique sheet-like morphology with uniform macroporous voids (macroholes). Moreover, the macrohole formation, mesoporosity and zeolitic properties of the meso-TSM material can be controlled in a straightforward way by adjusting the length of the hydrothermal treatment. This newly developed material may imply great potential for catalytic redox applications and diffusion limitated processes because of its highly tunable character in all three dimensions (micro-, meso- and macroporous scale).
Address
Corporate Author Thesis
Publisher Kluwer Academic Place of Publication Boston, Mass. Editor
Language Wos 000301187600002 Publication Date 2011-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1380-2224;1573-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.624 Times cited 2 Open Access
Notes Fwo; Goa Approved Most recent IF: 1.624; 2012 IF: 1.348
Call Number (down) UA @ lucian @ c:irua:88367 Serial 1257
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Author Vernimmen, J.; Guidotti, M.; Silvestre-Albero, J.; Jardim, E.O.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Psaro, R.; Rodríguez-Reinoso, F.; Meynen, V.; Cool, P.
Title Immersion calorimetry as a tool to evaluate the catalytic performance of titanosilicate materials in the epoxidation of cyclohexene Type A1 Journal article
Year 2011 Publication Langmuir: the ACS journal of surfaces and colloids Abbreviated Journal Langmuir
Volume 27 Issue 7 Pages 3618-3625
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Different types of titanosilicates are synthesized, structurally characterized, and subsequently catalytically tested in the liquid-phase epoxidation of cyclohexene. The performance of three types of combined zeolitic/mesoporous materials is compared with that of widely studied Ti-grafted-MCM-41 molecular sieve and the TS-1 microporous titanosilicate. The catalytic test results are correlated with the structural characteristics of the different catalysts. Moreover, for the first time, immersion calorimetry with the same substrate molecule as in the catalytic test reaction is applied as an extra means to interpret the catalytic results. A good correlation between catalytic performance and immersion calorimetry results is found. This work points out that the combination of catalytic testing and immersion calorimetry can lead to important insights into the influence of the materials structural characteristics on catalysis. Moreover, the potential of using immersion calorimetry as a screening tool for catalysts in epoxidation reactions is shown.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000288970900054 Publication Date 2011-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0743-7463;1520-5827; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.833 Times cited 19 Open Access
Notes Approved Most recent IF: 3.833; 2011 IF: 4.186
Call Number (down) UA @ lucian @ c:irua:88366 Serial 1557
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Author Mao, M.; Bogaerts, A.
Title Investigating the plasma chemistry for the synthesis of carbon nanotubes/nanofibres in an inductively coupled plasma-enhanced CVD system : the effect of processing parameters Type A1 Journal article
Year 2010 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 43 Issue 31 Pages 315203-315203,15
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A parameter study is carried out for an inductively coupled plasma used for the synthesis of carbon nanotubes or carbon nanofibres (CNTs/CNFs), by means of the Hybrid Plasma Equipment Model. The influence of processing parameters including gas ratio for four different gas mixtures typically used for CNT/CNF growth (i.e. CH4/H2, CH4/NH3, C2H2/H2 and C2H2/NH3), inductively coupled plasma (ICP) power (501000 W), operating pressure (10 mTorr1 Torr), bias power (01000 W) and temperature of the substrate (01000 °C) on the plasma chemistry is investigated and the optimized conditions for CNT/CNF growth are analysed. Summarized, our calculations suggest that a lower fraction of hydrocarbon gases (CH4 or C2H2, i.e. below 20%) and hence a higher fraction of etchant gases (H2 or NH3) in the gas mixture result in more 'clean' conditions for controlled CNT/CNF growth. The same applies to a higher ICP power, a moderate ICP gas pressure above 100 mTorr (at least for single-walled carbon nanotubes), a high bias power (for aligned CNTs) and an intermediate substrate temperature.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000280275200007 Publication Date 2010-07-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 17 Open Access
Notes Approved Most recent IF: 2.588; 2010 IF: 2.109
Call Number (down) UA @ lucian @ c:irua:88365 Serial 1724
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Author Bogaerts, A.; Eckert, M.; Mao, M.; Neyts, E.
Title Computer modelling of the plasma chemistry and plasma-based growth mechanisms for nanostructured materials Type A1 Journal article
Year 2011 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 44 Issue 17 Pages 174030-174030,16
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this review paper, an overview is given of different modelling efforts for plasmas used for the formation and growth of nanostructured materials. This includes both the plasma chemistry, providing information on the precursors for nanostructure formation, as well as the growth processes itself. We limit ourselves to carbon (and silicon) nanostructures. Examples of the plasma modelling comprise nanoparticle formation in silane and hydrocarbon plasmas, as well as the plasma chemistry giving rise to carbon nanostructure formation, such as (ultra)nanocrystalline diamond ((U)NCD) and carbon nanotubes (CNTs). The second part of the paper deals with the simulation of the (plasma-based) growth mechanisms of the same carbon nanostructures, i.e. (U)NCD and CNTs, both by mechanistic modelling and detailed atomistic simulations.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000289512700030 Publication Date 2011-04-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727;1361-6463; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.588 Times cited 25 Open Access
Notes Approved Most recent IF: 2.588; 2011 IF: 2.544
Call Number (down) UA @ lucian @ c:irua:88364 Serial 463
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